Interpretive Summary: Septoria tritici blotch (STB) is one of the most important fungal diseases of wheat. It currently is the most important disease of wheat in Europe and is among the top two or three most economically damaging diseases of this crop in the United States. The cost of fungicides to control the disease can be very high, considering that wheat is the most widely planted food crop. To disseminate information about the biology of the pathogen and best methods of disease management, information on pathogen biology, epidemic spread and control was collated and summarized. Disease symptoms and spread were illustrated and control methods presented. This information will be of use to plant pathologists to understand and deploy the latest methods of disease management.

Technical Abstract:
Septoria tritici blotch (STB) is one of the most important fungal diseases of wheat. It currently is the most important disease of wheat in Europe and is among the top two or three most economically damaging diseases of this crop in the United States. The cost of fungicides to control the disease can be very high, considering that wheat is the most widely planted food crop. STB occurs throughout the world in countries as diverse as Argentina, Ethiopia, Iran, the United States, the Netherlands, Russia, New Zealand and Australia. Epidemics can be particularly devastating in developing countries, such as those in East Africa. Severe epidemics of STB can cause reduce wheat yields by 35 to 50%. In the United States, STB is second only to wheat rust in terms of importance, and it is the number one disease of wheat in Russia and most countries of western Europe. The cost of fungicides to control the disease can be very high, and their application may not be economical depending on the price of grain. Approximately 70% of the estimated volume of fungicide used on cereals in Europe is used to control STB, with economic losses at of at least $400 million dollars. In the United States alone, STB can severely affect yield and cause economic losses of more than $275 million dollars each year to wheat growers. The recent release of the M. graminicola genome is an important step in fully understanding and identifying genes and processes that can be used to help control this important pathogen.